This Master’s Thesis focused on nitrogen residues in blasted ore caused by underground stoping. The objective of the study was to find out how much explosives are not detonated correctly and how much nitrogen appear in blasted ore. In addition the target was to find out if the opening method of the stope and the utilization of blasting socks affects the levels of nitrogen residues.

The literature review represents the fractions and flows of nitrogen from explosives to the environment and demonstrates the main factors influencing the incident of the detonation. Also the principles of drill & blast planning used at the mine is presented for prefacing the experimental part of the study.

In the experimental study, dissolution analyses were performed for crushed ore samples from three individual stopes. To observe sources of errors, drill hole deviations, blasting vibrations and laser scans of the blasted stopes were implemented. Furthermore drilling and blasting reports along with sensitizing tests of the explosives were documented.

According to the results of dissolution analyses, the average total nitrogen content of test stopes was 38 g/t and approximately 30 % of used explosives detonated incorrectly. However, because of the occurred decreasing of particle sizes due to sampling methods, the results can be considered overestimating the nitrogen amounts. Nevertheless the results are approximate for evaluating factors of the study.

Concluding the study, the opening method with raise bored opening holes shows potential to decrease nitrogen residues of blasting compared to the conventional long hole raise. The results of utilizing blasting socks were insufficiently reliable to show their connection to nitrogen residues. Blasting socks though can be considered as auxiliary blasting equipment to prevent the spillage of explosives in drill holes located in fracture zones.